PML regulates p53 stability by sequestering Mdm2 to the nucleolus

Bernardi, R., Scaglioni, P., Bergmann, S., Horn, H., Vousden, K. and Pandolfi, P. (2004) PML regulates p53 stability by sequestering Mdm2 to the nucleolus. Nature Cell Biology, 6(7), pp. 665-672. (doi: 10.1038/ncb1147)

Abstract

The promyelocytic leukaemia (PML) tumour-suppressor protein potentiates p53 function by regulating post-translational modifications, such as CBP-dependent acetylation(1,2) and Chk2-dependent phosphorylation, in the PML-Nuclear Body (NB)(3). PML was recently shown to interact with the p53 ubiquitin-ligase Mdm2 (refs 4-6); however, the mechanism by which PML regulates Mdm2 remains unclear. Here, we show that PML enhances p53 stability by sequestering Mdm2 to the nucleolus. We found that after DNA damage, PML and Mdm2 accumulate in the nucleolus in an Arf-independent manner. In addition, we found that the nucleolar localization of PML is dependent on ATR activation and phosphorylation of PML by ATR. Notably, in Pml(-/-) cells, sequestration of Mdm2 to the nucleolus was impaired, as well as p53 stabilization and the induction of apoptosis. Furthermore, we demonstrate that PML physically associates with the nucleolar protein L11, and that L11 knockdown impairs the ability of PML to localize to nucleoli after DNA damage. These findings demonstrate an unexpected role of PML in the nucleolar network for tumour suppression.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Horn, Dr Henning and Vousden, Karen
• Authors: Bernardi, R., Scaglioni, P., Bergmann, S., Horn, H., Vousden, K., and Pandolfi, P.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Nature Cell Biology
• ISSN: 1465-7392